Describe structural arrangement andorganization of plant cells.Explain the biochemistry ofphotoreceptor complexes likephytochrome, cryptochromes andphototropins.Outline the basics of photosystems and photosynthesis. Differentiate between light and dark reactions of photosynthesis andphotorespiration.Explain photosynthetic pathways likeC3, C4, C2 and CAM. Highlight the significance of plantgrowth regulators in the developmentof plants, stages of plant development-ripening, germination, dormancy and senescence.Explain the mechanism of water andmineral balance in plants, Nitrogenmetabolism, fixation and itsimportance.Discuss the importance of secondarymetabolites and their applications. Explain various bio-geochemical cycleslike, carbon, nitrogen, sulphur and phosphorus cycle and metabolism oftoxic substances in plants.